As part of the Tube's 150th birthday celebrations, Metropolitan Locomotive
Number 1 takes a test drive on the underground ahead of a special
anniversary service on Sunday.

A special steam-powered service is set to run for ticketholders between Kensington Olympia and Moorgate on Sunday, 150 years to the day that the Metropolitan Line first took paying passengers on the London Underground.

Howard Collins, chief operating officer for the London Underground, and Sam Mullins, director of the London Transport Museum, discuss how a vintage Metropolitan Line steam locomotive and carriage have returned to the track to mark the 150th anniversary of the Tube.